(1) Field of the Invention:
The present invention relates to an outer heat insulating structure on a building roof. More particularly, the invention relates to improvement on the outer heat insulating structure on the building roof, which structure is designed such that while heat insulating boards are closely arranged longitudinally and laterally on the surface of the roof of the building, hold panels are also closely arranged longitudinally and laterally in a plane while being upwardly spaced from the heat insulating boards.
(2) Description of the Prior Art:
The temperature which a human body feels in a room depends upon room temperature as well as radiation heat from a ceiling surface. For this reason, there have been proposed outer heat insulating structures on the building roofs particularly in the case of the concrete buildings so that the heat insulating boards are closely spread all over the roof. Such heat insulating structures can warm the entire building, mitigate cooling-down particularly early in the morning, interrupt direct sunshine in summer, prevent roof slabs from accumulating heat through utilization of proper ventilation and shading effect, and eliminate sultriness at night which may be caused by accumulated heat.
The conventional outer heat insulating structures of this type generally have a unit structure to make the installation and removal thereof facilitated and them to be easily applied to newly constructed buildings as well as existing buildings. As shown in FIG. 11, heat insulating boards 4 are closely arranged longitudinally and laterally in a plane spaced upwardly while a spacing 3 (the lower air layer) is kept between the upper surface 1a of a body of a building and the boards, and hold panels 6 are arranged longitudinally and laterally in a plane spaced upwardly while a spacing 5 (the upper air layer) is kept between the heat insulating boards and the hold panels. The corner portions of the adjacent panels are held up by support legs 7 supported by the building body, and the panels are integrally tightened by means of fixing caps 9.
Such an outer heat insulating structure on the building roof has merits in that since the heat insulating boards are closely paved over the upper surface of the building body while being spaced therefrom, the heat insulating effect can be enhanced by the double heat insulating structure consisting of the air layers and the heat insulating boards, and that even when rain, snow and the like enters the interior of the heat insulating structure, it can be dried to its original state through spontaneous ventilation due to the presence of the air layers, thereby keeping the heat insulating performance at a high level for a long period of time.
However, since there exists the space under the hold panels, when a strong wind A such as in a typhoon blows as shown in FIG. 11, the hold panels are sucked upwardly by a suction force F produced due to the difference in pressure P.sub.1 and P.sub.2 formed on the upper and lower sides of the hold panels 6, that is, the negative pressure produced by a high speed stream on the upper side, so that there is a problem that the panels are peeled off and scattered to the surrounding area.
It is necessary from the standpoint of safety to assuredly prevent the hold panels from being peeled off by the difference in pressure caused between the upper and lower sides of the hold panel as mentioned above.
For this reason, according to the conventional structures, the hold panels are made of concrete to have enough weight to withstand local wind pressure, or alternatively, the panels are directly fixed to the building body by means of anchors, an adhesive or the like. However, if the panels are made heavier, there only rises a danger when the weight of the panels exceeds the tolerable superimposed load capacity of the building, but also the durable life of the building is caused to be shortened. Further, there occurs a problem in building construction is that the heavier the panel, the poorer are the constructing performance and maintenance property. On the other hand, in the case that the hold panels are directly bound to the building body, there may occur the fatal defects that the constructing workability and the maintenance property become poor, but also the water-proof layer is damaged.